Many techniques have heretofore been known for raising sensitivity of silver halide light-sensitive materials. However, all of them involve such defects as deterioration in graininess of image and increase in fog. Thus, techniques for raising sensitivity without such defects have been desired.
An example of raising sensitivity by devising a new layer structure for the light-sensitive material includes a technique of comprising a fine particle reflecting layer being positioned under and adjacent to an emulsion layer to raise the sensitivity of the emulsion layer by utilizing light-scattering properties of the fine particle reflecting layer. This technique is disclosed in Research Disclosure No. 134 (1975), p. 47, 13452.
This technique is surely effective for raising sensitivity, but sometimes it remarkably deteriorates graininess so much that it causes difficult problems when practised.